Volcano at work

In a building project that could take eons, Mt. St. Helens giveth what she once blew away

December 04, 2005|By Robert Cross, Tribune staff reporter

MT. ST. HELENS, Wash. — The first sighting from Washington Highway 504 tells the story in an instant. Round a bend and there, suddenly, a major star of the Cascade Range appears, a standout mountain poking through a gray blanket of foothills in the Gifford Pinchot National Forest: Mt. St. Helens National Volcanic Monument.

It's certainly majestic--yet menacing, too, once you become familiar with the background.

From the mountain, fluffy clouds climb slowly toward the sky, emanating from a circular, snow-brushed grin. Mt. St. Helens smiles down on us, puffing smoke as if enjoying an invisible cigar.

FOR THE RECORD - This story contains corrected material, published Dec. 6, 2005.

Those who know the past history--and who doesn't?--realize the damage that this volcano can do. The most recent example would, of course, be the violent eruption of May 18, 1980. At 8:32 a.m. to be precise.

In mid-October on the veranda of the Coldwater Ridge Visitor Center, U.S. Forest Service ranger Mike Byers held up a photograph for a bunch of tour bus passengers, RV wanderers and high school field-trippers. It was a picture of a cliche mountain, the stuff of cartoons and the Paramount logo--cone-shaped, snow-capped, symmetrical, 9,677 feet tall.

"That picture was taken at 8:27 a.m., May 18, 1980," Byers said. Five minutes later, the mountain blew and immediately became an imperfect structure with a crater on its side, a cone deflated and distorted by the terrible forces deep within the Earth.

It spewed dense clouds of ash and flying boulders, shredding trees, killing 57 people and untold wildlife (including an estimated 1,500 elk), stripping soil down to bare rock and filling valleys with debris as far away as 14 miles--the largest landslide in recorded history. Further convulsions, less severe, occurred over the next few months. And Mt. St. Helens had lost more than 1,300 feet off its top. Various sources reckon the current height at 8,363 to 8,365 feet.

The day I first went there this October was remarkably clear, and Byers' audience could plainly see the results of the 1980s blast: that hole in the side, big Coldwater Lake down below. "Before 1980, it was called Coldwater Creek," Byers remarked. "That's the impact the landslide had. It filled in this valley with 200 to 300 feet of debris, blocked some of the side valleys, changed the whole landscape"

But his point was that the horrific explosion came without some sort of precursor; nothing about it set off an alarm. There had been episodes of rumbling and minor earthquakes over the years, but they had led to nothing. That sort of thing was also occurring in the spring of 1980, but without any outward signs of a huge volcanic buildup.

"In the two months before May 18, 1980, we had about 10,000 earthquakes. By the end of March we had craters opening up on the summit, we had steam and ash coming out of the summit," Byers said.

"In 1980 that area where we see that big hole on the north side, that area started growing outwards, bulging outwards--toward the north and toward the sky at about five feet a day. It was kind of strange, sort of like the world's largest pimple."

But even that wasn't considered a sign of what would follow.

Suddenly, on May 18, the pimple collapsed and havoc ensued. "Liquid rock from inside the Earth--magma--had been trying to get out," Byers said. "It found a mountain in the way and actually started pushing up and breaking that mountain apart, five feet a day."

I returned to the mountain about a week after my visit to the Coldwater Ridge Visitor Center, and this time I headed directly for the Johnston Ridge Observatory. St. Helens had changed considerably. Now snow covered most of the peak, and clouds obscured the pinnacle. Its plume of vapors remained visible, however, and enormous developments were going on inside that massive crater formed in 1980.

A sign at the observatory entrance showed a sketch of Mt. St. Helens rendered crudely in crayon. "Get your fresh lava," said the sign. "Local organic lava, one dump truck of lava every three seconds."

Mt. St. Helens started throwing out lava again in October of last year, but not very far, as things turned out. Back then, the headlines sounded dire. "Ready to blow," said The Tribune on Oct. 4, 2004, and, a week later, "Quakes shake peak, but no eruption yet."

For the past year, it has been burping magma and slowly rebuilding the portion of St. Helens that the 1980 event wiped out. In 100 to 150 years or so, it might be cone-shaped again if the magma doesn't get out of hand.

Officials at the Johnston Ridge Observatory believe that another major cataclysm won't catch them by surprise this time. They have faith that their monitoring systems are far more sophisticated than they were 25 years ago. Even so, employees tend to look at the seismograph each morning before they pour their coffee.

Not to worry, said ranger Pamela McCray, "even though it's erupting something like a Honda Civic every second and a half."